2 2 Cautionary Statements Our presentation today may include forward-looking statements within the meaning of Section 27A of the Securities Act of 1933 and Section 21E of the Securities Exchange Act of 1934. Such statements involve risk and uncertainty, including financial, business environment and projections, and related to matters that are not historical facts. Such statements are preceded by, followed by or include the words “believes,” “can,” “expects,” “plans,” “anticipates,” “should,” “enhances,” “estimates,” “forecasts,” “will” or similar expressions. Additionally, this presentation contains forward-looking statements relating to future performance, goals, strategic actions and initiatives and similar intentions and beliefs, including, without limitation, statements with respect to Sigma-Aldrich Corporation’s (the “Company,” “we,” “us” or “our”) expectations, goals, beliefs, intentions, outlook, plans and the like regarding future sales, earnings, free cash flow, share repurchases, acquisitions and other matters. These statements are based on assumptions regarding the Company operations, investments and acquisitions and conditions in the market the Company serves. The Company believes these assumptions are reasonable and well founded. The statements in this presentation are subject to risks and uncertainties, including, among others, certain economic, political and technological factors. Actual results could differ materially from those stated or implied in this presentation, due to, but not limited to, such factors as (1) global economic conditions, (2) changes in pricing and the competitive environment and the global demand for the Company’s products, (3) fluctuations in foreign currency exchange rates, (4) changes in research funding and the success of research and development activities, (5) failure of planned sales initiatives in our Research and SAFC business units, (6) dependence on uninterrupted manufacturing operations and global supply chain, (7) changes in the regulatory environment in which the Company operates, (8) changes in worldwide tax rates or tax benefits from domestic and international operations, including the matters described in Note 10 – Income Taxes to the Company’s Consolidated Financial Statements included in Item 8, Part II in the Company’s Annual Report on Form 10-K for the year ended December 31, 2011 (the “10-K”), (9) exposure to litigation including product liability claims, (10) the ability to maintain adequate quality standards, (11) reliance on third party package delivery services, (12) an unanticipated increase in interest rates, (13) other changes in the business environment in which the Company operates, (14) the outcome of the outstanding matters described in Note 11 – Contingent Liabilities and Commitments, to the Company’s consolidated financial statements included in Item 8, Part II in the 10-K and (15) acquisitions or divestitures of businesses. A further discussion of the Company’s risk factors can be found in Item 1A of Part I of the 10-K. The Company does not undertake any obligation to update these forward-looking statements. • With over 60 percent of sales denominated in currencies other than the U.S. dollar, management uses currency adjusted growth, and believes it is useful to investors, to judge the Company’s local currency performance. Organic sales growth data presented herein excludes currency impacts, and where indicated, acquisition impacts. The Company calculates the impact of changes in foreign currency exchange rates by multiplying current period activity by the difference between current period exchange rates and prior period exchange rates; the result is the defined impact of “changes in foreign currency exchange rates” or “changes in FX.” While we are able to report currency impacts after the fact, we are unable to estimate changes that may occur later in 2012 to applicable exchange rates. Any significant changes in currency exchange rates would likely have a significant impact on our reported growth rates due to the volume of our sales denominated in foreign currencies. • Management also uses the following non-GAAP measures to judge its performance and ability to pursue opportunities that enhance shareholder value: adjusted net income and EPS; adjusted operating income margin (reconciled on Slide 14); and free cash flow (provided on Slide 17). Due to the uncertain timing of future restructuring and other special charges we are unable to include these charges in the 2012 diluted adjusted EPS forecast or provide reconciliation to the corresponding GAAP measures. Management believes this non-GAAP information is useful to investors as well. Reconciliations of GAAP to non-GAAP information are included in the Company’s April 24, 2012 earnings release posted on its website, www.sigma-aldrich.com, and in the Appendix – Reconciliation of GAAP to Non-GAAP Financial Measures beginning on Slide 12. | 
